特大断面硐室底鼓控制技术研究

为解决王庄煤矿大断面支架换装硐室底鼓量大的问题,采用理论计算和数值模拟方法对特大断面硐室底板变形破坏特征进行了分析,提出了反底拱和底板锚索群加固2种底鼓控制技术,并用FLAC3D数值模拟软件建立了2种底鼓控制方案的数值计算模型,并对其支护效果进行了对比.结果表明:硐室底板破坏深度达到2.2m,塑性区半径达12m,底鼓控制难度大,特大断面硐室底板锚索群控制底鼓效果明显优于反底拱.现场应用表明实施底板锚索群注浆加固措施后,巷道最大底鼓量为80 nmm,能较好地控制底鼓.     

深井软岩大断面硐室二次加固技术及稳定性分析

软岩大断面硐室的支护问题被视为困扰当今煤矿生产的主要难题之一。针对磴槽煤矿600m埋深十平泵房硐室传统支护效果不佳的情况,采用锚网喷、锚索及二次注浆联合支护方案对硐室进行修复加固,并采用底角锚杆及反底拱来防止底鼓的产生,取得了较好的支护效果。为验证该支护方案的机理,应用了大型非线性有限元计算软件ABAQUS进行模拟计算,通过对计算结果的分析,得到了硐室开挖后的应力变化及塑性区的扩展规律,并验证了锚杆组合拱理论和锚索悬吊理论。     

深井大断面硐室反底拱技术研究应用

井巷开采逐步向深层推进,地压大导致巷道拱帮开裂、底鼓的速度加快,直接影响到大断面硐室的使用寿命。针对硐室底鼓治理,该文从施工方案的选择、施工方法等几个方面进行了论述,在反底拱支护技术方面进行了积极探索与实践。     

基于FLAC仿真计算的巷道底鼓预控技术"

采用FLAC模拟分析的方法,对某矿红土层中巷道采用底拱和反底拱2种不同支护方式下围岩力学行为进行了研究,系统分析了不同支护方式下围岩应力、位移及塑性区的变化情况。研究结果表明:采用反底拱进行硐室支护后,硐室底鼓量为50 mm,顶板监测点下沉量为50 mm,均为采用底拱支护技术的1/9左右;底板的垂直流变速度为8.64 mm/d,为采用底拱支护技术的1/3;最大应力明显降低。反底拱支护显著提高了围岩的强度和承载能力,有效地控制了软岩巷道的底板变形膨胀。     

显德汪矿-200m水平泵房硐室群全断面支护技术

为了解决显德汪矿-200 m泵房硐室群大面积变形破坏的难题,首先通过现场调研初步分析了变形破坏的原因,其次对硐室开挖扰动的应力场进行了区域划分,按应力集中程度的大小由表及里依次形成应力卸载圈、强应力集中圈、次强应力集中圈和应力稳定圈。在此基础上提出了双壳加固理论,由深浅支护体形成的支护壳共同作用,使巷道处于稳定状态。最后结合-200m水平泵房硐室群的实际情况,设计采用了以锚杆索配合深、浅注浆作为双壳支护的主体,同时辅以底角锚索束+反底拱的全断面联合支护维修方案,取得了较好的控制效果。     

富水软岩大断面巷道支护工艺

新上海一矿北翼轨道大巷为软岩巷道,掘进断面较大,原采用"锚网喷+锚索+29U型钢支架+复喷"支护,一次支护为锚网喷+锚索。一次支护15d后,巷道即出现顶板下沉及底鼓现象。后来通过不断摸索与实践,改用"锚网喷+锚索+单层钢筋网反底拱+钢筋混凝土碹+壁后注浆"支护,分2次进行,有效地控制了巷道变形,加快了施工速度,使得巷道平均月进尺由原来的50m左右提高到了75m,达到了预期效果。     

特大断面硐室软岩变形机理及控制

为了有效控制王庄煤矿支架换装硐室围岩的变形破坏,分析了特大断面硐室围岩变形破坏机理.认为断面大、岩性差、二次应力高及支护参数不合理是围岩变形破坏的主要原因,并提出了“及时支护,高强、高预紧力长锚杆、注浆锚索、长锚索分层协调支护”的特大断面硐室支护技术.在王庄煤矿断面96 m2的特大断面支架换装硐室成功应用.     

软岩硐室反拱形底板加固技术研究

针对黄陵一号煤矿软岩硐室底鼓量大的问题,根据通讯硐室的工程地质条件,对软岩硐室的底鼓机理进行了分析,提出了底板超挖反拱浇筑混凝土加底锚杆、锚索群综合加固技术,并通过FLAC~(3D)数值模拟软件对硐室底板加固前后的效果进行了对比。现场工程实践表明,该方案有效地控制了大断面硐室底鼓的发生。     

显德汪矿软弱围岩大变形硐室群加固实践

冀中能源股份有限公司显德汪矿-200 m水泵房硐室群周围围岩软弱,应力非常复杂,通过采用锚网索支护＋注浆＋底角锚索束＋反底拱等多重控制围岩稳定的支护方案,有效地保证了硐室群整体稳定性,取得了良好的社会及经济效益。     

井底大断面关键永久硐室围岩变形机理及其控制技术

为解决井底大断面换装硐室一次支护围岩大变形问题,基于成庄煤矿大断面硐室围岩地质力学条件和变形特征,采用理论分析、数值模拟和现场试验的方法从大断面硐室围岩应力分布特点和支护承载结构稳定性两方面分析了大断面硐室围岩变形破坏的原因,并针对硐室围岩变形破坏的特征及其控制要求,研究提出在注浆原位加固提高原有锚网支护与围岩共同形成的支护承载结构完整性和强度的基础上,进一步采用全长预应力锚固强力锚索增强支护承载结构的稳定性的技术方案,对成庄矿井底大断面关键永久硐室进行二次加固。试验结果表明,巷道围岩变形量为8mm,底鼓为13mm,有效控制了硐室围岩的大变形。     

Current situation and future trend of China rare earth luminescent material industry

<正>Rare earth luminescent material is one of the most important application sectors of rare earths.China enjoys the exceptional advantage to develop rare earth luminescent material for its abundant rare earth resources.After several decades'endeavor,China's rare earth luminescent material industry,headed by rare earth phosphor for lamp and LED and high efficient rare earth energy-saving light source,has been gradually developed into a scale industry.China has become a major production base of rare earth phosphor for lamps and rare earth     

China rare earth market review

正June 1~10,2014Rare earth market remained weak.Quoted price of rare earth products was similar to that in May.There was no sign of recovery in downstream market.The market of NdFeB magnetic materials and phosphor was depressed.Catalyst,polishing powder and ceramic industries remained inactive.Demand from downstream industry was soft.Consumers purchased on their needs.Suppliers had strong intention to sell.Prices of rare earth products     

Annual Report analysis of Chinese rare earth-related listed companies in 2013

<正>Chinese rare earth-related listed companies have published their 2013 annual reports.It can be understood from their reports that production and operation activities of Chinese rare earth-related companies were still heavily affected by macro economy and industrial policies.They basically followed the steps of national economy.In 2013,world economy recovered slowly but the economy     

Market opportunities and challenges for rare earth polishing powder

正1.Status of rare earth polishing powder Rare earth polishing powder with high content of cerium oxide began to replace iron oxide for glass polishing and became one of the key materials in glass polishing process since 1940.Compared with traditional iron oxide,rare earth polishing powder has many advantages,such as fast polishing rate,high polishing quality and long service life.It can achieve good surface quality and improve operation conditions.For example,in lens polishing,the polishing work that cerium     

Baotou Research Institute of Rare Earths developed a new RE alloy preparation technology

正Pyrometallurgy Laboratory of Baotou Research Institute of Rare Earths had independently developed a new preparation technology of rare earth alloy for NdFeB.The alloy can remarkably enhance the coercivity of NdFeB magnet but also evidently reduce the production cost of the magnet.The new master alloy was prepared in the kA pilot-scale electrolytic cell by the independent technology.The rare earth master alloy can be used as the raw material for NdFeB.Compared     

Market and recycling of NiMH battery

<正>Market status and future trend of NiMH battery1.Global market of small NiMH battery Global market size of small NiMH batteries declined year on year since 2011.The trend will continue to 2018,at the rate of 5%to 10%annually.Demand for small NiMH batteries will be stable gradually.Many electrical apparatuses are powered by the built-in lithium battery today,which is the main reason for the shrunk market of small NiMH batteries.But,for some products,small NiMH     

China rare earth market review

正September 1-10,2014 Affected by the National Day holiday,rare earth transaction was stagnant and the market showed a weak steady state.As there was no good news for downstream market,some products with flat demand would likely rally slightly for some time to     

2014 second batch of rare earth quota released

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矿用防爆轴流对旋主要通风机叶片ANSYS模态分析及应用

高效节能矿用防爆对旋主要通风机的叶片是主要通风机运行的关键部件,叶片在运行时不断受到气流的作用力,从而使叶片产生振动,当叶片振动的频率与叶片的固有频率接近时,容易产生共振从而导致叶片的断裂。一旦叶片断裂时,对主要通风机的安全运行产生致命的影响,从而导致矿山、化工等企业发生重大事故,将会产生不可估量的损失。基于有限元分析软件ANSYS,对高效节能矿用防爆轴流对旋主要通风机叶片进行模态分析及产生对应的六阶模态频率,对主要通风机叶片的运行频率、固有频率及产生的共振问题进行了原理分析,并且解决了叶片频率共振的问题,从而为主要通风机叶片结构设计提供理论依据,并对主要通风机叶片的安全运行提供保障。     

2013 NdFeB export analysis

<正>China totally exported nearly 24,000 tonsof NdFeB products during 201 3,including 18,825 tons of permanent magnet,valued USD 1.34 billion at an average price of 71.4 USD/kg;3,277 tons of NdFeB magnetic powder,valued USD 1 01 million at an average price of 30.9 USD/kg;1,334 tons of strip casting ribbon,with total export value of USD 74million at an average price of 55.3 USD/kg;and 586